Mercurial > hg > orthanc
diff OrthancFramework/Resources/ThirdParty/base64/base64.cpp @ 4044:d25f4c0fa160 framework
splitting code into OrthancFramework and OrthancServer
author | Sebastien Jodogne <s.jodogne@gmail.com> |
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date | Wed, 10 Jun 2020 20:30:34 +0200 |
parents | Resources/ThirdParty/base64/base64.cpp@79178122842c |
children |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/OrthancFramework/Resources/ThirdParty/base64/base64.cpp Wed Jun 10 20:30:34 2020 +0200 @@ -0,0 +1,179 @@ +/* + base64.cpp and base64.h + + Copyright (C) 2004-2008 René Nyffenegger + + This source code is provided 'as-is', without any express or implied + warranty. In no event will the author be held liable for any damages + arising from the use of this software. + + Permission is granted to anyone to use this software for any purpose, + including commercial applications, and to alter it and redistribute it + freely, subject to the following restrictions: + + 1. The origin of this source code must not be misrepresented; you must not + claim that you wrote the original source code. If you use this source code + in a product, an acknowledgment in the product documentation would be + appreciated but is not required. + + 2. Altered source versions must be plainly marked as such, and must not be + misrepresented as being the original source code. + + 3. This notice may not be removed or altered from any source distribution. + + René Nyffenegger rene.nyffenegger@adp-gmbh.ch + + ------------------------------ + This version has been modified (changed the interface + use another decoding algorithm + inspired from https://stackoverflow.com/a/34571089 which was faster) +*/ + +#include "base64.h" +#include <string.h> +#include <vector> + +static const std::string base64_chars = + "ABCDEFGHIJKLMNOPQRSTUVWXYZ" + "abcdefghijklmnopqrstuvwxyz" + "0123456789+/"; + +static inline bool is_base64(unsigned char c) { + return (isalnum(c) || (c == '+') || (c == '/')); +} + +void base64_encode(std::string& result, const std::string& stringToEncode) +{ + const unsigned char* bytes_to_encode = reinterpret_cast<const unsigned char*> + (stringToEncode.size() > 0 ? &stringToEncode[0] : NULL); + size_t in_len = stringToEncode.size(); + + result.reserve(result.size() + in_len * 4 / 3 + 10); + + int i = 0; + int j = 0; + unsigned char char_array_3[3]; + unsigned char char_array_4[4]; + + while (in_len--) { + char_array_3[i++] = *(bytes_to_encode++); + if (i == 3) { + char_array_4[0] = (char_array_3[0] & 0xfc) >> 2; + char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4); + char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6); + char_array_4[3] = char_array_3[2] & 0x3f; + + for(i = 0; (i <4) ; i++) + result += base64_chars[char_array_4[i]]; + i = 0; + } + } + + if (i) + { + for(j = i; j < 3; j++) + char_array_3[j] = '\0'; + + char_array_4[0] = (char_array_3[0] & 0xfc) >> 2; + char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4); + char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6); + char_array_4[3] = char_array_3[2] & 0x3f; + + for (j = 0; (j < i + 1); j++) + result += base64_chars[char_array_4[j]]; + + while((i++ < 3)) + result += '='; + + } +} + +// old code from René Nyffenegger. This code is slower +void base64_decode_old(std::string& result, const std::string& encoded_string) { + size_t in_len = encoded_string.size(); + int i = 0; + int j = 0; + int in_ = 0; + unsigned char char_array_4[4], char_array_3[3]; + + result.reserve(result.size() + in_len * 3 / 4 + 10); + + while (in_len-- && ( encoded_string[in_] != '=') && is_base64(encoded_string[in_])) { + char_array_4[i++] = encoded_string[in_]; in_++; + if (i ==4) { + for (i = 0; i <4; i++) + char_array_4[i] = base64_chars.find(char_array_4[i]); + + char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4); + char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2); + char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3]; + + for (i = 0; (i < 3); i++) + result += char_array_3[i]; + i = 0; + } + } + + if (i) { + for (j = i; j <4; j++) + char_array_4[j] = 0; + + for (j = 0; j <4; j++) + char_array_4[j] = base64_chars.find(char_array_4[j]); + + char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4); + char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2); + char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3]; + + for (j = 0; (j < i - 1); j++) + result += char_array_3[j]; + } +} + + +// new code from https://stackoverflow.com/a/34571089 +// note that the encoding algorithm from this page was slower (and bugged !) +// this code is not using std::vector::find + +// static init equivalent to: +// decode_indexes.assign(256, -1); +// for (int i=0; i<64; ++i) +// decode_indexes[base64_chars[i]] = i; + +static const int decode_indexes[] = { + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63, + 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1, + -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, + 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, + -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, + 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 +}; + + +void base64_decode(std::string& result, const std::string &stringToDecode) { + + result.reserve(result.size() + stringToDecode.size() * 3 / 4 + 10); + + int val=0, valb=-8; + for (std::string::const_iterator c = stringToDecode.begin(); c != stringToDecode.end(); ++c) + { + size_t index = static_cast<size_t>(*c); + if (decode_indexes[index] == -1) + break; + val = (val<<6) + decode_indexes[index]; + valb += 6; + if (valb>=0) { + result.push_back(char((val>>valb)&0xFF)); + valb-=8; + } + } +}